What are my errors in freestyle? (video)

I have started to swim recently 3/4 times per week. Basically I swim around 2500m (1h) including different types of legs (freestyle 90%; breast, back and fly:10%). My problem is that it has been more than ten years since last time I swam with a coach and if I ever had a good technique now it is rusty. Besides now I am in China and it is quite difficult to find a suitable coach because of language issues. So maybe you can help me out if I leave footage of myself here, and point out my errors. In a second stage I will try to figure out how to solve them. Thanks!!

Me trying freestyle:

As for my best performance in 100m event it is 1'20" and in 1500m it is 30'. And my goal is to make it 1'15" and 25' respectively, so any suggestion to make it possible is very welcome.

Re: What are my errors in freestyle? (video)

Re: What are my errors in freestyle? (video)

Perhaps you should focus more on a good streamline when you push off the wall. There is now a "bend" in your body and legs are not close together.
Debaru made also some good points. If you fix them your body will be more straight and causes less drag.

I am not sure whether you could improve on more bodystrength. Specially your core. It seems that upper and lower body are a bit disconnected.

Re: What are my errors in freestyle? (video)

I agree with Debbie. Maintain a narrow path of travel, you're slipping out when breathing. Think of everything on same axis that rotates together for stroke while the head rotates even more to breathe, yet on same axis. Imagine a dot on top of your head that points forward at all times, your dot doesn't. Your arms seem to be used for the rotation therefore your crossing center and loosing propulsion.

It takes constant work and drilling to minimize this (I have to every time I practice ) but you seem to have good basic position

Re: What are my errors in freestyle? (video)

Thank you WhyNot, yeah i know i dont push off the wall very well, but now it is not my priority concern, however i do concern about doing the flip turn right, is it correct? a guy told me that i dont do it properly and i could hurt my back. I do not get to understand it. What´s wrong with my flip turn? As for the core, how is it going to help me swim better? I thought the core has not much to do with swimming technique, as you can see i am not an expert.

Thank you Steve, good advice that of the dot on my head, but i cannot figure out a way to prevent my body from sinking everytime i have to breathe. Although it might be that i am not sinking when breathing but i go everytime sunk and it is more noticeable when breathing because you can see the neck extension to the top of the water surface.

I have read somewhere that we have to narrow our shoulders along the whole cycle (both over and underwater stroke) and i have seen that i dont do it either, how to do it? i´ve looked for youtube videos but found nothing.